Fuse switch



A. G. MILLER May 22, 1934.

FUSE SWITCH Filed Feb. 25, 1932 IN VEN TOR.

A TTORNEY,

Patented May 22, 1934 UNITED STATES PATENT OFFICEy 8 Claims.

This invention relates to fuse switches and more particularlyto those adapted for use in high tension electric circuits wherein the fuse melts to open the circuit in case of an overload,

and has for its principal object to effect positive withdrawal of the fuse conductor element when the overload occurs, thereby preventing arcing oi' the high tension current between the fused portions of the conductor.

Another important object oi' the invention is to provide a visible signal which indicates that the circuit has been opened.

In accomplishing these and other objects oi' `the invention, I have provided improved details l5 of structure, the preferred form of which is illustrated in the accompanying drawing, wherein:

Fig. 1 is a perspective view ot a fuse switch constructed in accordance with my invention, and illustrating the fused portion of the conductor withdrawn from the cartridge.

Fig. 2 is a longitudinal vertical sectional view through the switch cartridge illustrating the fusible element in functional position.

Fig. 3 is a detail end elevational view of the lower end of the fuse cartridge, particularly illustrating the spring for eiecting withdrawal of the fuse element from the cartridge.

Fig. 4 is a horizontal sectional view on the line 1 -4, Fig. 2.

Referring more in detail to the drawing:-

1 designates an insulator adapted for support by a suitable bracket 2 that clamps the intermediate portion of the insulator. The opposite ends of the insulator are provided with electric terminal clamps 3 and 4 to which one of the high tension circuit wires is connected.

The lower terminal 3 includes a depending fork-shaped bracket 5 having spaced hookshaped ends 6 forming arcuate seats 7 to hing- 4 edly support the lower end of the cartridge, later described.

The upper terminal 4 is provided with'a forwardly extending yoke 8 having a latch-engag- 5 ing notch 9 to receive a latch member on the upper end ot the switch cartridge now described.

A The cartridge includes an inner tube 10 constructed of bakelite or similar material, having a threaded upper end 11 for mounting a metallic head member 12 adapted to engage in the yoke 8. The tube is of sulcient length to extend substantially below the insulator, and sleeved on its lower end is a metallic foot member 13 which is adapted to be secured to the tube by a set screw 14 threadedly mounted in the foot (Cl. Zoll- 117) porcelain sleeve 15 to reinforce and protect the 60 inner sleeve from exposure to the elements.

The foot member 13 is provided with oppositely directed pins 16 and 17 for seating in the hookshaped ends of the bracket member 5, whereby an electric connection is made from the bracket ta the foot member, and whereby the cartridge pivotally mounted. The head 12 is provided at its upper end with a threaded neck 18 having an upwardly extending lug 19 for connecting the upper end of a fuse element later described. The open upper end oi' the head member is closed by a suitable cap 20 threaded on the neck 18 to preve t moisture from entering the upper portion of t tube.

Extending laterally from the head member is an ear 21 for pivotally mounting a latch lever 22 for engaging the notch 9 to retain the upper end ot the member in electric contact with the yoke member 8. 'I'he latch is adapted to be operated by a suitable ring-shaped handle member 23 80 fixed to the pivot 24 carrying the latch.

The construction thus far described is conventional i'or this type of fuse switch, and specifically forms no part of the present invention.

Formed on the lower front tace of the foot member is a downwardly and outwardly curved arm 25 having its lower end 26 terminating adjacent the end oi' the inner tube 10, as is clearly illustrated in Fig. 2. The outer curved lace of the arm is provided withoutwardly extending flanges 27 and 28 adjacent its side edges to'iorm a grooved seat 29 i'ora spring element 30.

The s'pring element 30 includes a normally tlat metal spring having sufficient width to be received between the iianges 27 and 28 and has its 95 upper end attached by a screw 31 in the upper end'oi' the groove 29, while its body portion is curved about the arm and its lower end terminates in a curve 32 extending toward the axis of the tube 10.

Located on the i'oot member 13 directly above the arm 25 is a shoulder portion 33 for mounting a terminal screw 34 that is threadedly engaged in a recess 35 formed in the foot member.

The fuse element includes upper and lower 105 flexible conductor sections 36 and 37 connected together by a fusible connector 39 housed within the upper end of the tube 10, as illustrated in Fig. 2. The upper end of the upper conductor section is Secured to the lug 19 by a screw 40 and 110 the lower end of the conductor 37 is threaded downwardly through the tube and over the spring member` 30 for attachment to the screw 34 previously described, as illustrated in Fig. 2. The lower section of the conductor element thus tensions the spring member over the arm when the fuse element is in functional position in the cartridge, so that when an overload occurs in the circuit and the fuse 39 melts, the tension of the spring will effect withdrawal of the lower section oi' the conductor from the tube 10, as illustrated in Fig. l, thereby preventing arcing and burning within the cartridge.

To assemble a fuse element in a cartridge constructed.as described, the conductor sections are threaded through the tube and the upper section is secured to the lug 19 by the screw 40, and the lower end of the conductor section 37 is drawn about the curved end of the spring and over the top thereof to be secured in position by the screw 34. The foot portion of the cartridge is then applied to the terminal 3 with the pins 16 and 17 thereof seated in the seats 7 formed on the lower ends of the fork member 5. The head portion of the cartridge is then swung into position to engage the yoke 8, at which time the latch 22 engages the notch 9 to secure the cartridge in functional position.

The current then flows through the terminal 4, yoke 8, the head member l2, lug 19, conductor section 36, fuse 39, conductor section 37, terminal screw 34, and through the foot member 13 to the fork-shaped bracket on the lower terminal 3, therebycompleting circuit of the conductor and connecting the terminals 3 and 4.

In the case of an overload of the circuit, the excessive current melts the fuse 39, which releases the spring 30 to snap the lower conductor section from the tube l0. as shown in Fig. l. The loose wavy end of the fuse and the outwardly depending spring provide indication `that the circuit has been opened, so that the linemen can tell from the ground which of the fuses has opened the circuit.

From the foregoing it is apparent that I have provided means for positively withdrawing the fused portion of the conductor to prevent arcing of thecircuit after the fuse 39 is melted.

What I claim and desire to secure by Letters Patent is:

l. In a fuse switch of the character described including a tube, head and foot members on the upper and lower ends of the tube, a fusible conductor element housed within the tube and have ing its'-` ends connected to said head and foot members, an arm on one of said members, and spring means tensioned over Vsaid arm and engaging said fusible conductor element for eiecting withdrawal of the fuse element from the tube upon ifusing thereof.

, 2. In a fuse switch of the character described including a tube, head and foot members on the upper and lower ends of the tube, a fusible conductor element housed within the tube and havirjg its ends connected to said head and foot memfbrs, an arm on one of the members, and a spring strip having onev end fixed to the arm and its other end extended over the farm and engaged with said conductor element for effecting Withdrawal of the fuse element from the tube upon fusing thereof.

3. In a fuse switch of the character described including a tube, head and foot members on the upper and lower ends of the tube, a fusible conductor element housed within the tube and having its ends connected to said head and foot members, an arcuate-shaped arm on one of the members, and a spring adapted to be tensioned over the arm incidental to application of the fusible conductor for effecting withdrawal of the fuse element from the tube upon fusing thereof.

4. In a fuse switch of the character described including a tube, head and foot members on the upper and lower ends of the tube, a fusible conductor element housed within the tube and having its ends connected to said head and foot members, a curved arm on the foot member, and a spring associated with said arm for effecting withdrawal of the fuse element from the tube upon fusing thereof.

5. In a fuse switch of the character described including a tube, head and foot members on the upper and lower ends of the tube, a fusible conductorelement housed within the tube and having its ends connected to said head and foot members, a curved arm on the foot member and having a groove in its outer face, and a flat spring having one end attached to said arm and arranged to seat in said groove with its opposite end terminating adjacent the lower end of said tube, whereby said conductor is drawn over the outer face of said spring to retain the spring in tensioned condition when the fusible conductor is in functional position.

6. In a fuse switch of the character described including a tube, a fusible conductor element housed within the tube, a curved spring-supporting member associated with said tube, and a leaf spring bendable over said supporting member and engaging the fusible conductor element for eecting withdrawal of the fuse element therefrom upon fusing thereof.

7. In a fuse switch of the character described including a tube, head and foot members on the upper and lower ends of the tube, a fusible conductor element housed within the tube and hav ing its ends connected to said head and foot members, a curved arm on the foot member, and

Ya. at spring having one end attached to 4said arm and arranged to be extended over the curved portion of the arm with its opposite end temilnating adjacent the lower end of said tube, whereby said conductor is drawn over theouter face of said spring to retain the springin tensioned condition for effecting withdrawal of said fuse element upon fusing thereof.

8,. In a fuse switch of the character described, a tube, a fusible conductor element having the major portion thereof housed within the tube, means for connecting one end of the fuse element exteriorly of the tube, means for connecting the opposite end of the fuse element within the tube, an' arm member underlying the fuse element exteriorly of -the tube, means for mounting the arm on the tube, and a spring cooperating with the arm member to effect withdrawal of the fuse element from the tube uponv fusing thereof.

ARTHUR G. MILLER. 

